The present invention relates generally to anti-spill ports for fluids. More particularly, the present invention relates to the transference of fluids through the anti-spill port into a fluid holding device.
FIG. 1 illustrates a typical prior art thermal inkjet pen. This inkjet pen includes a main unitary body housing (101) of a suitable non-hygroscopic plastic material for outer chambers and a soft plastic (105) inner frame that is favorable for bag film staking. The inner frame of the housing (105) contains a staked aluminized polyethylene film bag (110) for storing the ink. There is also a stainless steel spring (130) inside the bag that is submerged in the ink to provide the necessary capillary backpressure at the print head of the pen to prevent ink from dripping out of the pen.
The pen further includes an output or print head support section (140) that has a small output opening (145) adjacent to which is mounted a thin film thermal inkjet print head (120). The print head support section (140) has interior walls that define the contour of a large diameter standpipe and an air accumulating section.
As seen in FIG. 1, the air accumulating section (145) of the standpipe is the upper portion thereof just beneath the wire mesh filter (115). Air accumulates in this section (145) when the pen is operating in the orientation shown in FIG. 1. As a result of the wire mesh filter (115), air bubbles entering the standpipe from the print head are trapped. The filter (115) prevents any trapped air in the ink filled bag (110) from being drawn down into the standpipe.
The thermal inkjet pen also typically includes an electrical connection (150). The electrical connection (150) provides the ability for signals from the inkjet printer in which the pen is place to communicate with the inkjet pen. The electrical connection (150) is comprised of a plurality of electrical contacts that enable the printer""s controller to address each of the heating elements in the print head (120).
After such an inkjet pen in manufactured, it must move down a line to be filled with ink. To accomplish this, the inkjet pen moves to an ink-filling station, a needle is inserted into the ink filling port (125) in the inkjet pen, and ink is injected through the needle into the body of the pen. After a predetermined quantity of ink has been injected into the inkjet pen, the needle is withdrawn from the pen, the filled pen is moved down the line to the next station where a stainless steel ball cork is inserted into the fill hole to keep the ink in the inkjet pen body. Additionally, a Pet plastic coated plastic film patch (160) is staked on the exterior to completely seal the ink fill port. This patch has the same diameter as the soft plastic that is exposed. This inkjet pen has a lever (135) to ease installation and removal of the pen from the inkjet printer carriage.
A typical prior art ink filling port is illustrated in FIG. 12. This port is comprised of a through hole (1201) in the soft plastic inner frame (1205) of the inkjet pen. An internal ridge or detent (1210) keeps the ball cork in position and provides a primary seal.
One potential problem is that as the needle is withdrawn from the inkjet pen, the needle may still have ink on its outer surface. The ink may be transferred onto the ink fill mechanism and, if it has corrosive characteristics, it may cause the needle housing to become gummy and require frequent cleaning to prevent its decay over a period of time. Frequent cleaning cycles would also cause loss of productivity. Additionally, as the pen moves, the ink may spill out of the fill hole and cover the machinery used to convey the inkjet pen. This could eventually require that the line be shut down to clean up spilled ink in order to prevent corrosion of the line equipment. Also, the ball cork may slip down into the inkjet pen, thus causing the pen to be removed from the line and money lost as a result. There is a resulting unforeseen need for an improved product that prevents ink from spilling out and at the same time wipes the needle on its return stroke.
The present invention encompasses an anti-spill filling port for a fluid. The preferred embodiment of the anti-spill filling port is for use in an inkjet pen.
The filling port is part of the inner frame of the pen body that is molded from soft plastic and has an interlock with the outer hard plastic frame. The invention embodies six xe2x80x9cpetalsxe2x80x9d that are molded in a semispherical form and congregate at the center of the fill port. Each petal is connected to the other by a thin plastic diaphragm that acts as a spill inhibiter. When punctured by the fluid fill needle, the thin diaphragm tears only up to the radius of the needle leaving the rest still connected to each other to act as a wiper. The memory effect of the membranes returns the petals to close in after the needle is retracted. The upper portion of each petal acts as hinge when the needle is inserted.